Tube cleaning method



Jan.,2o,197o C. mi DN'ATQ 3,490,468

Tui-3E CLEANING METHOD Filed Apri1`1o, 19e? i s sheets-sheet 1 iJ CARMEN P. D! DONATO I ATTORNEYS Jan- 20, 1970 c. P. nl D'cNA-ro TUBE CLEANING METHOD" 3 Sheecs--SheerI 2 Filed April l0, 1967 CARMEN P. DI DONATO BY 0%,MmE/g @mw ATTORNEYS Jan-20,1970 QR-Drown@ '35490,:468'

` i TUBE CLEANING METHOD Filed Apriilo, 1967 s 'sheets-sheet s CARMEN P-Dl DONATO ATTORNEYS United States Patent O 3,490,468 TUBE CLEANING METHOD Carmen P. Di Donato, 8659 Prescott Drive, Chesterland, Ohio 44026 Filed Apr. 10, 1967, Ser. No. 629,598 Int. Cl. B08b 3/10, 3/02, 1/02 U.S. Cl. 134-22 10 Claims ABSTRACT OF THE DISCLOSURE cooled, and a testing station where the coil isl tested for leaks.

DISCLOSURE The present invention relates as indicated to a tube cleaning method, having particularly advantageous use in the cleaning of relatively long lengths of coiled or straight tubing.

The cleaning of coiled tubing of the type used, for example, in refrigeration equipment, has posed a persistent problem which has to date not been satisfactorily solved. During the tube forming and coiling operations, grease, oil, dirt and other deleterious material is deposited on both the interior and the exterior surfaces of the coil. If the coiled tubing is to be used in the indicated environment, thorough cleaning of the inside of the coil is necessary to avoid contamination of the uid refrigerants, with cleaning both inside and outside also being desirable prior to annealing to avoid such material from lbeing baked to such surfaces at the relatively high annealing temperatures.

Present methods of cleaning the interior and exterior of coiled tubing are unsatisfactory for a number of reasons. Initially, as far as the inventor is aware, the cleaning process is primarily manually performed, a costly and time-consuming operation at best. To clean the inside of the coil, which may typically be -6 feet in diameter and have a total coil length of 1600-1700 feet, a solvent is introduced into the coil and a solvent absorbing material, e.g. cotton, subsequently blown through the coil, followed by a drying step which comprises blowing air or the like through the tube to evaporate any solvent remaining therein. Apart from the time consuming aspect of this cleaning operation, it is understandably very diicult to thoroughly clean the coil interior. The outside of the coil is at present cleaned simply by wiping the same with a solvent-saturated material, for example a rubber sponge or the like, with the degree of cleaning obviously being limited here as well.

A further consideration is that coil lengths are continually increasing thereby making essentially manual cleaning techniques just that much more dilicult and costly. Moreover, with the coil lengths now visualized and possible in accordance with constantly improving coil forming apparatus, present cleaning techniques will become increasingly more outmoded.

In regard to straight tube lengths, customarily in the range of 20-30 feet, individual cleaning is excessively time consuming and thus costly, and there is a tendency for this reason to forego cleaning of straight tubes entirely unless the intended use of the tubing absolutely requires such cleaning.

With the above in mind, a primary object of the present invention is to provide a novel method for cleaning tubing, both coiled and straight, of indeterminate lengths.

A further object of the invention is to provide a method for the cleaning of straight and coiled tubing which comprises the passing of heated cleaning uid through the interior of the tubing while simultaneously subjecting the exterior thereof to such cleaning fluid for simultaneously cleaning such exterior surface.

A further object of the present invention is to provide such a cleaning process which is entirely automatic and in which the coils or essentially straight tube lengths are automatically indexed through the several cleaning stations in timed sequence.

A further, more specific object of the present invention is to provide a tube cleaning process which comprises the steps of initially introducing cleaning fluid in the form of a liquid, normally water into the coils or straight tubes to be cleaned, with such iluid either illing or partially lling the coil. The coil is `subsequently subjected both to relatively high temperatures causing boiling of the fluid within the coil and impinging action of liquid cleaning uid on the entire exterior surface thereof to clean the same. Liquid nid is thereafter circulated through-the coil interior to flush away the oil and dirt-laden cleaning uid, and a cooling fluid, normally air, thereafter circulated therethrough to dry the coil interior and reduce the temperature of the coil sufliciently to permit immediate handling hereof. The tubing may thereafter be indexed through a testing station to detect leaks in the coil.

These and other objects and advantages of the present invention will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principle of the invention may be employed.

In said annexed drawings:

' FIG. 1 is a side elevational view of the coil and tube cleaning apparatus of the present invention, with certain parts being broken away better to expose the apparatus interior and with the coils Ibeing shown in spaced relation for automatic indexing through the apparatus;

. FIG. 2 is a sectional view taken on line 2 2 of FIG. 1 showing more clearly the manner in which the opposite ends of the coil are operatively connected for flushing the interior of the coil;

FIG. 3 is a sectional view taken on line' 3-3 of FIG. 2;

' FIG. 4 is a sectional View taken on line 4-4 of FIG. 1;

FIG. 5 is a fragmentary side elevational View similar to FIG. 1, with the coils in this form, however, being suspended for indexed movement through the cleaningv apparatus;

FIG. 6 is a sectional view taken on line 6-6 of FIG. 5;

FIG. 7 is a fragmentary side elevational view similar to FIG. 1 showing a preferred arrangement for cleaning straight tube lengths;

FIG. 8 is a sectional view taken on line 8-8 of FIG. 7, and

FIG. 9 is a schematic diagram of the. preferred circuit of the invention.

Referring now in more detail to the drawings, wherein like parts are indicated by like reference numerals, and initially to the form of the invention illustrated in FIGS. 1-4, the tubing illustrated in such figures is in coiled form being supported on a pallet or tray in turn supported for rolling movement on conveyor rollers commonly designated at v12. The opposite ends of theroller 12 are rotatably mounted in brackets 13 carried by bracketsupport members' 14 suitably attached `to the apparatus-housing. It Will be understood that the coil diameter, total coil length, and coil material will vary depending on a vparticular plant operation, `and it will become apparent that the principles ofl the present invention are readily adaptable to varying tube lengths and coil diameter and lengths. As shown, each coil C might typically comprise. copper tubing having an .inside vdiameter of approximately ,1/2 inch coiled'to a coil diameter of 5-6 feet, with the total coil lengths being approximately 160Q-1700 feet. As above noted, inthe drawing and coil forming process, oil, grease and dirt are accumulated both inside and outside the coil all of which must be desirably removed from such surfaces for'the reasons indicated. A Y

EachV tray 10 is4 provided at each corner thereof with upwardly extending retainer hookscommonly designated at 19101" tliepurpose of'retainingmthe coil C onthe tray.

As' will be understood, the'hooks 19 can be positioned on the tray most advantageously to control the. shifting ofthe coil during the cleaning operation. f

The pallets 10 supporting the coils C are driven over the rollers 12 by drive chains 20 and 22. FIG. 2, which carry drive lugs 23, FIG. l, which drivingly engage the trailing end of thefpallets 10. The chains and 22 are driven in a well-known manner by speed reducer motors 24, only one of which is visible in FIG. 2, which are mounted on brackets carried by the apparatus housing.

As best shown in FIG. 2, the opposite ends and 32 of the coil C extend upwardly through openings provided therefor in locking bar 34, with clamping means or the like (not shown) being provided to releasably retain the ends. The coil ends are preferably vertically positioned at a predetermined elevation in any suitable manner and maintained in such vertical position throughout the cleaning operation.

A pair of upper conveyor drive chains 40 and 42,

FIG. 2, are provided for driving the upper coil ends 30 and 32, with each of such chains carrying a plurality of spaced lugs 43 adapted to contact the locking bar 34 for positively moving the same. Each of the upper drive chains 40 and 42 is driven by a speed reducer motor 44, only one of which is shown in FIG. 2, which is mounted on the apparatus housing by a bracket assembly 45..'I'he motors 44 and the previously described motors 24 for driving the. lower drive chains 20 and 22 are preferably synchronized for driving the upper and lower drive chains at the same speed. As will be hereinafter described, the motors 24 and 44 are also simultaneously actuated for indexing the coils through the apparatus.

A Washing station is generally indicated at 50 and is enclosed by housing section 52 which comprises an integral part of the apparatus housing previously referred to. Suitable heating means, which may comprise commercially available electric or gas fired heating equipment, schematically andv commonly shown at 53, are mounted preferably. within the housing 52 for heating the interior thereof to a predetermined temperature, for example ZOO-600 F. It will be understood that the desired temperature will depend in large measure on the type. of coil or tube being cleaned, and in certain circumstances supplementary heating means of the type described may be.y unnecessary to satisfactorily clean a particular tube or coil length. An elevated bottom wall 54 is provided in the intermediate region of the housing for a purpose to be hereinafter made apparent.

Fluid supply pipe 60 is connected at onev end to a longitudinal header 62 in turn communicating With branch lines commonly designated at 63 which 'extend through the top ofthe housing 52, and terminate in discharge nozzles 64 disposed slightly below the top of the enclosure and .directed `downwardly.A for --impinging contact on the coils C. It is preferred that the cleaning uid comprise water at a temperature near boiling for a thorough cleaning of the coil exterior, and the Water can be obtained from any suitable source, for vexample a conventional boiler (not shown). It willbe noted that the nozzles 64 extend for a substantial distance longitudinally within the housing 52 to ensure a thorough cleaning of the coil exterior.

As previously indicated, the coil ends 30 and 32 are vertically positioned prior to the entry into the housing 52. As the coils are. indexed through the housing, each in turn is positioned below a flushing station generally indicated 7atV- 70; The Vflushingfstation 70 includes an air cylinder 72 to which is operatively attached .a plunger 74'. The latter, as best seen'in FIG. 2, is formed with a generally bell-shaped bottom opening 76 adapted to receive the coil end 30 when the. plunger 74 is moved downwardly by the air cylinder. l c

The plunger 74 is 'formed with a longitudinal, central opening 78 adapted to be aligned with the coil end-30 when'ftheplunger`74'is inoperative position, with .the opposite end of the opening 78-communicating .with fluid line. 80 which in turn communicates with Water supply line 60 through branch line 81. Air lines 82 and84 are operatively connected to the Vair cylinder 72 for supplying and exhausting air therefrom to raise and lower the plunged 74. It will thus be seen that when the plunger 74` is in its lower position, with the coil end 30 received in opening76 thereof, water at the noted high temperature, is. supplied to thecoil end 30 from the supply line 60 for circulation through the interior of the coil.

The cleaning uid is exhausted from the coil end 32 by means substantially the same as described above. Thus, anair cylinder carries a plunger 94, with the cylinders 92 and 72 being preferably synchronously operated Whereby the plunger 94 is lowered to receive the coil end 32 simultaneously with the lowering of the plunger 74 to receive the coil end 30. When the respective plungers are in their lower position and cleaning water supplied through line 80 to the plunger 74, the incoming water circulates throughfthe coil and to the. plunger 94 and exhaust line 96 communicating therewith, With thev latter communicating .with a drain area in any suitable manner. The interior of the coil is thus thoroughly flushed with the cleaning water to removethe undesirable particles adhering to the inside surface of the coil. At the end of thev cleaning cycle, which maybe controlled in a conventional manner by a timer or the like, the plungers 72 and 74 are retracted and the coils indexed by the driver conveyors.

A drying station generally indicated at 100 is provided downstream from the flushing station 70 for drying and cooling the previously cleaned coil.rThe drying `station is l desirably outside the heating zone of the housing and comprises at least one cylinder 102 similar to cylinders 72 and 92 previously described, which has mounted therein a plunger 104 adapted to be lowered over the coil end 30. The plunger 104 communicates with air line 106 which isconnected to a source yof pressurized air. Thek cylinder is actuated to lower or yraise the plunger 104 by control lines 108 "and'110.` The actuation of cylinder 102 is preferably in timed relation with the actuation of cylinders 72 and 92 to facilitate the indexing of the coils through f the several stations. A second cylinder can if desiredl be provided for coupling to the coil end 32, or the latter may simply be left open and the drying air emitted therethrough. The drying station is preferably spaced from the flushing station 70 a distance equal to a multiple of the distance of a single indexed movement of the coils.

A central exhaust duct 120 and branch ducts 122 and 124 are provided for exhausting the interior of the housing4 52. Such exhausting may be periodic, if circumstances,l

permit; and the exhaust pipes are preferably well insulated to' reduce the heat loss therethrough.

The bottom wall is. sloped toward center, with a central drain opening being provided for draining the water from the area beneath the flushing station 70 to the oor from which it can be drained or otherwise removed as desired.

In the form shown, a testing station generally indicated at 150 is provided following the drying and cooling station 100 for testing for possible leaks in the coils C. The bottom wall 54 in such region includes inclined ramp sections 152 and 154 and a connected lower wall section 155. Side sections 156 and 157 form with the ramp and lower wall sections a tank area -for receiving water W. The oor 14 in the region of the thus formed tank is recessed as indicated at 158 to accommodate the tank bottom to provide the desired tank depth.

As illustrated in FIGS. 1 and 4, the coil C when in the central region of the tank is entirely submerged, excepting the coil ends 30 and 32, which extend upwardly through the locking bar 34 for reception by plungers 160 and 162, respectively, operatively connected to air cylinders 164and 166, respectively, all of the type previously described. In order to maintain the coil ends 30 and 32 at a predetermined elevation to synchronize the automatic operation, supporting bars 168 and 170 are provided extending inwardly from the supporting frame generally indicated at 172 for supporting the opposed ends of the locking bar 34 as the pallets traverse the testing station.

TheY plunger 160 is operatively connected to air line 174 which in turn communicates with a pressure gauge 176. An air supply line 178 supplies air to the line 174 through the pressure gauge 176 at a predetermined pressure controlled by the latter, all in a well-known manner. The exhaust line 180 operatively connected to the plunger 162 communicates with a valve 182 for closing such exhaust line during pressure buildup in the line 174 and in the coil C. An exhaust line 184 directs the air from the valve 182. It will thus be seen that any leakage in the coil C can be readily detected visually by merely observing the water tank.

As above indicated, the coils C and pallets 10 supporting the same are preferably automatically indexed through the several treating stations. Such automatic indexing can be realized in any suitable manner, for example by means of one or more limit switches extending into the path of either one of the coil ends 30 or 32 when the same has reached a predetermined position adjacent one of the several stations. One such arrangement is shown in FIG. 2 wherein a limit switch 200 is mounted by bracket 202 to the housing 52 and is provided with a pivotally mounted arm 204 which extends into the path of the coil end 32 when the same reaches the ushing station. The arm 204 is rotated by the coil end to open the circuit through the conveyor drive motors, as will hereinafter be more specically described when particular reference is made to FIG. 9.

The operation of the invention thus far described is as follows. The coils C are placed either at the coil forming station or immediately thereafter on the trays or pallets 10 for movement through the described apparatus, with each pallet 10 being spaced from the succeeding and preceding pallet a predetermined distance to permit automatic indexing as above described. Prior to the delivery of a particular coil to the heated region of the housing 52, the coil is partially or completely illed With cleaning fluid, normally water, With such lling being effected automatically or manually. The water is preferably at a relatively high temperature to reduce the time Within the enclosure that it takes the water to reach boiling temperature thereby to provide as along a period of time as possible for the boiling water to absorb the oil, grease, etc. on the interior of the coil.

As the coil and tray are longitudinally indexed through the housing 52, the exterior of the coil C is subjected to the Water emanating from the several water lines 63 thereby to thoroughly clean the same. Prior to the indexing of the coil to the flushing station 70, the Water partially lling the coil is brought to boiling temperature by the heat within the housing 52, with such boiling action removing the oil and other deleterious material adhering to the inside surface of the coil and suspending the same in the boiling liquid. As will be understood, the time it takes for the water to reach boiling temperature and the boiling period will depend upon the temperature of the water admitted to the coil during the partial illing operation, the temperature within the housing, and the timing of the indexing cycle. If desired, the ends of each coil as it is indexed through the washing station could be adapted to receive pressure responsive cap means to permit higher temperatures to be reached in the coil thereby more completely to dissolve deleterious material adhering to the interior coil wall.

The coil with the water boiling therein is eventually indexed to the flushing station 70, and the coil ends 30 and 32 are there automatically coupled to the plungers 74 and 94 as described. Cleaning water preferably near boiling temperature is then circulated through the coil for flushing the oil and dirt-laden water therefrom outwardly of the coil through exhaust -line 96. This flushing action continues for aperiod predeterminedly established by the timer which forms part of the control system. The injection is then terminated and the plungers`74 and 94 are thereafter raised by the air cylinders 72 and 92, respectively, and the pallet 10 indexed to the drying and cooling station 100, and the succeeding pallet and coil indexed to the flushing station 70.

At the drying and cooling station 100, the water remaining in the coil is flushed therefrom, with the air circulating through the coil serving to dry the interior of the coil and to reduce the temperature thereof.

The cooled and dried coil is thereafter indexed to the testing station and the coil ends 30 and 32 operatively coupled to plungers and 162 as above described. The air pressure is built up in the coil and any leakage therein can be readily detected by observation. The sub- =merging of the coil C serves further to reduce the temperature of the coil, desirably to the point where it can be manually handled. It will be understood that if conditions permit, the stations 100 and 150 could be combined, with the drying of the interior of the coil and the testing for leakageof the coil being accomplished at a single work station.

There is shown in FIG. 5 a modied form of the invention in which the coiled tube is suspended for i11- dexed movement through the apparatus. Where appropriate, the same reference numerals are employed to designate previously described subject matter.

In the FIG. 5 form, the coil C is suspended on a hook 220 carried by an overhead carrier member 222 which forms part of a preferably self-propelled carriage drive assembly of conventional construction. Each of such :members 222 is spaced from the adjacent such member so as to provide predetermined spacing of the coils C as they travel through the apparatus. Referring to FIG. 6, each member 222 is operatively connected to a pair of track rollers commonly designated at 224 which are supported on an overhead monorail track 226, all in a Wellknown manner. The several members 220 are driven by means of a cable drive arrangement which comprises a cable 228 which extends serially through lblock members 230 each of which is formed with a central opening for receiving and clamping the cable 228. A yoke 232 is in turn operatively connected to each of the blocks 230, with the yoke 232 including upwardly directed arms 234, 236 which carry the rollers 234. The bottom of the yoke 232 rigidly mounts the hook member 220.

The cable drive arrangement is conventional and functions to simultaneously drive the several suspended coils. The cable is preferably driven by means suitably synchronized with the lower conveyor drive for controlled movement of the several suspended coils. The controlled indexing of the suspended coils through the several work stations can be accomplished by means previously described, with limit switches and timing means being preferably employed to retain a coil for a predetermined Iamount of time when it has reached a particular work station.

Several banks of water nozzles generally and commonly designated at 240 are provided within the housing 52. Each bank 240 includes a plurality of individual nozzles commonly designated at 242 directed generally toward the coil C movable therewithin. The nozzles 242 are supplied from a branch line 244 which is in turn operatively connected to ya main header 246, FIG. S.

The lower chain drive is essentially similar to that previously described, comprising a forward drive chain 250 andan upper return chain 252. The lower chain 250 carries a series of drive lugs 254 which are adapted to engage the stabilizingbars 256 similar in structure and function to the previously described bars 34. Thus, the opposite ends 30 and 32 of the coil extend upwardly through openings in the associated stabilizing bar 256 and yare clamped thereto, with the extreme end portions of such coil ends being at a predetermined vertical elevation for the reasons indicated. The stabilizing bar 256 is also maintained yat a predetermined vertical elevation by means of rails 258 and 260 mounted at the sides of the enclosure 52 in much the same manner as the rails 168 and 170 above described in particular reference to FIG. 4.

The flushing station 70 in the FIGS. 5-6 form of the invention is essentially the same as that previously described with reference to FIGS. 1-4. Thus, plungers 264 and 266 are operatively carried by cylinders 268 and 270, respectively, which are in turn mounted on brackets 272 and 274 lixedly secured to the enclosure '52, with the cylinders 268 and 270 functioning to automatically lower and raise the plungers for coupling the same to the Coil ends. The plunger 2,64 is supplied by a branch line 276 which in turn is supplied by the header 246. Cleaning water after passing through the coil C leaves the plunger 26.6 through exhaust line 278 for suitable discharge.

The drying station generally indicated at 100 is similarly essentially the same as that previously described with reference to the FIGS. 1-4 form of the invention. The drying station thus includes at least one cylinder, 280 to which is mounted a plunger 282 adapted to be lowered for receiving the upper end of the coil end 30. The plunger 282 is connected to a source of pressurized air, for example through line 284, for directing cleaning air through the coil C. The coil end 32 can be exhausted in the manner described, and, if desired, a second cylinder and plunger can be provided.

The housing 52 is vented by means of vent pipe 290 which communicates with the housing at the top thereof. A sloping false bottom generally indicated at 292 is also provided formed with a central drain 294 for draining the water directed through the several nozzles from the housing. Suitable heating means is provided (not shown) for heating the housing section 52 in the manner previously described. The temperature within the housing can be varied depending upon the degree ofcleaning desired, with the temperature in the area of the housing immediately preceding the flushing station 70 being preferably well above the boiling point of water.

The operation of the FIGS. 5-6 formof the invention should be apparent from the above. The previously formed coils are suspended from the hooks 220 preferably near the coil forming station, with the hooks 220 being suitably spaced to accommodate indexing thereof through the several work stations. The coil ends are inserted the stabilizing bar 256 and clamped thereto as described, and the coil is preferably partially filled with water before entering the housing 52. As the coils are progressively indexed through the enclosure, the elevated temperatures within the enclosure in the area thereof preceding the flushing station 70 will cause the Water within each coil to boil so that oil, grease, dirt and the like contained interiorly ofthe coil as a result of the coil forming operation are dislodged therefrom. When each respective coil reaches the flushing station 70, the Water and suspended impurities are flushed therefrom thereby. providing a clean interior coil surface. The coil is thereafter indexed to the drying station 100 wherethe c oil interior is dried and the coil cooled. The coil C is thereafter preferably delivered to a leak testing'station (not shown), which' may be 0f the type previously referre to in the FIGS.- 1-4 form of the invention.v l

The FIGS. 5-6-form of lthe invention has partcula application where the total coil length is not excessive and the coil weight therefor. not prohibitively high. The suspending of the coils C has the advantage. of more fully exposing the coil exterior thereby to provide more thorough cleaning of the exterior surface thereof by the water nozzles.

There is show nv schematically in FIG; 9 t-he preferred circuit for providing the vdesired automatic-indexingot` the coils inthe FIGS. A1-,6 forms of the invention through the several work stations. The limit'switch200xiscon-` nected in serieswith timing switch 402-Which in turn is connected in vparallel to motors 24 and 44 whichdrive.

, respectively-the lower and upper conveyorfchains. The

circuit further includes a switch 408 mechanically coupled to the limit switch 200, and a timing relay 410.

In operation, the switches 200 and:l 402 are normally biased closed thereby closing the circuit through motors 24, 44 and driving the upper and` lower conveyor chains 40, 42 and 20,-22, respectively. When a coil reachesthe flushing station 70, the limit switch 200 is opened as described thereby opening the circuit to the motors 24 and 44 and closing the switch 408 mechanically connected thereto. The closing of the switch 408 completes the circuit through the timing relay 410 thereby opening the timing switch 402. The limit switch 200 is preferably momentarily open, with the reclosing thereof opening the switch 408. However, the circuit through the motors 24 and 44 remains open until the timing switch 402s again" closed by the timing relay 410. This time period between indexing movements can be set as desired to accommodate the operations at the flushing, drying and testing stations. After such predetermined time has elapsed, the timing switch is again closed and the motors 24 and 44 actuated to index the coils, with such indexing movement continuing until the successive coil reaches the flushing station and reopens the limit switch 200'.

There is shown in FIG. 7 a further form ofthe invention, particularly suited for treating relatively short,

straight lengths of tubing. As appreciated, to thoroughlyv clean the interior and exterior of each individual tubev is a time-consuming and thus costly operation, with the result being that :at the present time straight tube lengths undergo little if any cleaning either interiorly or exteriorly. If the substantially straight tube lengths are lto Abe used inV environments which require relatively cleanvtube interiors, the presence of dirt, grease and other impurities on the inside surface of the coil might prohibit such use thereof. y v

In accordance with the invention lform illustrated in FIG. 7, the individual tubes shown commonly atl T are supported on a platform or pallet 300 with supportsA 302 and 304 being provided for elevating the respective ends' of the tubes for a purpose which will presently be made apparent. The rear support 304 is in the form of Va vertically adjustable slide block for lowering the adjacent tube ends to facilitate the flushing operation, as will be hereinafter specifically described with reference to FIG. 8. The tubes T are supported intermediate to their lengths by a cross member 306 positioned on the top face of the platform 300. The platform 300 is preferably driven by drive rollers 312 each shaft of which carries a sprocket 314 operatively driven by a chain 316 in conventional manner.`

ySeveral banks of nozzles commonly designated at 308 extend downwardly through the housing 52 to an yinner area above the tubes T, with the several nozzles being supplied by branch 310 and being turned at their ends toward the loading ends of the tubes which traverse the apparatus left to right, as viewed in FIG. 7. The leading ends of the tubes are thus subjected to the water stream emanating from the several banks of nozzles.

It is preferred that the tubes T be filled or partially filled prior to the flushing operation in order to provide a more thorough cleaning of the interior of the tube. With straight tube lengths, Waterfretention for the purpose indicated is somewhat of a problem and, in accordance with the present invention, meansare provided to selectively raise or lower the trailing end of the tubes on the platform 300 r pallet to alternately provide for retention of the water in the tubes, or for gravity draining of the water from the tubes. Thus, the tubes are shown in dashed lines in FIG. 7 with the opposite ends elevated relative to the intermediate central portion of the tubes thereby to retain any water delivered thereto. In the solid line showing of the tubes in FIG. 7, the trailing ends thereof are relatively lower than the forward intermediate portions thereof with the result that the water directed into such forward ends drains by gravity therefrom.

In accordance with the invention, the forward and intermediate supporting blocks 302 and 306 are stationary and the desired vertical positioning of the trailing ends of the tube is accomplished by vertical adjustment of the slide i block 304. The manner inwhich the slide block therefore is vertically adjusted is illustrated in FIG. 8. The pallet 300 carrier relatively adjacent the rear end thereof brackets 320 and 322 which are apertured for receiving shaft 324. The latter carries a pinion gear 326 and is formed longitudinally thereof with thread groups 3,28, 330, 332 and 334. The opposite ends of the shaft 324 are supported by bearing blocks carried by brackets 336 and 338 mounted on the pallet 300.

In the region of the housing 52 where it is desired to flush the previously partially filled tubes, the drive rollers are sectioned as shown in 340 and 342 to accommodate upwardly extending post support 344 which carries at the top thereof a rack 346. The post 344 is apertured to accommodate the adjacent ends of the roller shafts. More than one post 344 may be provided depending upon the desired length of the rack 346 relative to the spacing of the drive rollers.

The opposite ends of the several drive rollers extend through generally L-shaped supporting members 350 and 352 which are rigidly mounted on the walls of the housing 52. The drive sprockets 314 and chain 316 are mounted outside the support members 350 and 352, as clearly seen in FIG. 8.

Each of the threaded sections 328-334 formed on the shaft 324 receives a slide block 360, with the thread formations being formed so that each associated pair of blocks 360 converge or diverge depending upon the direction of rotation of the shaft 324.

Two pairs of jacking arms 362 are provided, each of which is pivotally connected as shown at 364 to each of the internally threaded blocks 360, with adjacent such arms 362 being pivotally connected to each other as shown in 366 in scissors fashion. The opposite, upper ends of each of the arms 362 are operatively connected to a jacking platform 368 the opposite ends of which carry the previously described slide blocks 304 which are slidably mounted within the hook retaining members 370 which extend upwardly from the pallet 300 at each s1de and rear corner thereof. To retain the slide blocks Withlrl the retaining members 370, a top 'retaining bar 372 is preferably provided. The jacking platform 368 is provided with a plurality of elongated slots commonly designated at 374 in the region thereof receiving the upper ends of the several arms 362. The arms 362 are slidably retained in the several slots 374 by pins 376 or the like, in conventional manner.

The jacking platform 368 is shown in solid lines in FIG. 8 in its lower-most position which corresponds to the position of the slide blocks 304 in FIG. 7, which position permits gravity draining of the flushing liquid through the tubes. In the dashed line, elevate-d position of the jacking platform 368, the trailing ends of the tubes are elevated, as shown in dashed lines in FIG. 7, which comprises the position of the platform prior to reaching the flushing station.

' In a normal operation of the FIGS. 7-8 form of the invention, the jacking platform 368 is elevated at some point substantially prior to the flushing station, for example, at the time the straight tube lengths are loaded on the platform. When the platform 368 is thus elevated, the tubes T can be partially filled with water andthe water retained therein. As the pallet 300 traverses the housing 52 lunder the controlled movement of the drive rollers 312, the elevated temperatures within the enclosure 52 as above described will effect boiling `of the water within the several tubes thereby serving more thoroughly to dislodge dirt, grease, and the like from the tube interior into suspension in the boiling water. The jacking platform 368 can be initially elevated in any suitable manner, for example, manually by providing a hexagonal-shaped recess or the like in either or both ends of the shaft 24 for insertion of a suitably shaped tool.

As the pallet 300 approaches the flushing area the gear 326 carried by the shafts 324 will drivingly engage the fixed rack 346 thereby prod-ucing rotation of the pinion 326 and shaft 324. The direction of rotation of the shaft 324 and the thread formations 328-334 aresuch as to produce divergent movement of each adjacent, pivotally connected pair of slide blocks 360, 'with the result that the jacking arms 362 are lowered thereby lowering the jacking platform 368. It will be understood that the extent to which the jacking platform 368 is lowered will depend upon the length of the rack 346. As the pallet 300 and the pinion 326 carried thereby advance past the rack 346, the jacking platform 368 will remain in its lower adjusted position, which position is slightly lower than the vertical elevation of the intermediate supporting member 306 thereby to permit gravity draining of the iiushing liquid through the tubes T. When the tubes have fully traversed the treatment zone, they can be removed in any suitable manner from the pallet 300 and the latter processed back to the tube loading position, wherein the platform 368 will again be raised as above described for receiving a succeeding group of tubes.

It will be noted that in the FIG. 7 form, the banks of nozzles 308 function to direct an impinging water stream on the exterior of the tubes T as well as dire-cting a hush- 1ng liquid stream through the interior of the coils, with the result that the tubes are cleaned both exteriorly and interiorly. If desired, the nozzles may be located substantially completely around the top and sides of the enclosure to facilitate the exterior cleaning of the tubes.

It will thus be seen that in fall of the several forms of the invention, the coiled and essentially straight tube lengths are cleaned both exteriorly and interiorly. With respect to the cleaning of the ycoiled tubes as shown in the FIGS. l-4 and FIGS. 5-6 forms of the invention, the

coils are automatically indexed thro-ugh the flushing, drying and, in connection with the FIGS. 1-4 apparatus, testing stations. The invention not only provides the high degree of cleaning required but essentially eliminates the need of skilled personnel thereby substantially reducing tube cleaning costs.

It will be apparent to those skilled in the art that various changes lwill suggest themselves to those skilled in the art without, however, departing from the lconcepts of the present invention, as defined by the appended claims.

Other modes of applying the principle of the invention may be employed, change being made as-regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

I Atherefore particularly point out and distinctly claim as my invention:

1.. The method of cleaning tubing comprising the steps of supporting said tubing for traversal through a series of stations, preliminarily at least partially filling said tubing with ycleaning liquid at a first station, subjecting the exterior of said tubing to impinging liquid contact at a second station for removing dirt and grease deposited thereon. during the tube forming operation, transporting the tubing from the second station to a third station, heating the exterior of said tubing, while at said second station and during traversal to said third station, to a temperature sucient to boil said cleaning liquid in said tubing to facilitate removal of dirt, grease and the like from the interior 4surface of said tubing at said third station, and flushing the interior of said tubing with flushing liquid at said third station for removing said dirt, grease and the like from said tubing interior.

2. The method of claim 1 wherein said tubing is in the form of a coil which is supported for transversal through a series of stations as aforesaid.

3. The method of claim 1 further comprising the step of subjecting the exterior of the tubing to elevated temperatures during the flushing step.

4. The method of claim 1 further comprising the step 25 of drying and cooling said tubing after flushing to permit substantially immediate handling thereof after said tubing has been cleaned.

5. The method of claim 1 wherein the step of subjectingvthe exterior of said tubing to impinging liquid contact is achieved by spraying the exterior with cleaning liquid.

6. The method of claim 1 further comprising the step of submergingthe tubing in liquid after iiushing and pressurizing the tubing interior to visually detect leaks therein, and subsequently drying :and cooling the tubing.

7. The method of claim 1 |wherein said tubing is in the form of a coil having ends which are received in plungers Icontaining openings through vwhich the ushing liquid passes during flushing of the interior of the tubing atthe third station as aforesaid. y

8. The method of claim 1 wherein said tubing com? prises individual lengths, and the ends of the individual lengths are elevated relative t-o theirintermediate regions prior to filling with cleaning liquid at the I'irst station for; retaining the cleaning liquid therein.

9. The method of claim 8wherein oneend; of,V each individual length of tubing is lowered relative tothe. intermediate region prior to flushing the interior of the tubing at the third station to permit gravity draining of liquid from the interior of the tubing. l

10. The method of claim 9 wherein nozzles are used for spraying iiushing liquid into the other.end ofsaid individual lengths of tubing for ushing theinterior of the tubing as aforesaid, and the tubing is moved relativeto the nozzles for spraying cleaning liquid on the exterior of said tubing to remove dirt and grease therefrom.

References Cited y UNITED STATES PATENTS 2,123,434 7/ 1938 Paulson et al. 2,918,925 12/ 1959 Dopler. l

FOREIGN PATENTS 405,915 2/ 1934 Great Britain. 526,109 6/ 1956 Canada.

MORRIS O. WOLK, Primary Examiner JOSEPH T. ZATARGA, Assistant Examiner U.S. Cl. X.R. 

